The second fire was started on February 28 at about 10pm and was quickly put out by the fire service.

Both were recorded as arson and referred to police.

However they will not be investigated and the police have not passed the cases to any other agencies.

A fire service spokesman said: “Starting any kind of fire deliberately is dangerous, but it is particularly dangerous to start deliberate fires by a busy road like this.

“Deliberate fires not only create danger themselves but also tie up crews who could be needed to save a life at a genuine emergency.”

However, a police spokesman said: “There is no evidence to suggest the caravan fires were started criminally, as they could have been set alight by their owners.”

Charred: Inside the wreckage of the first blaze...

...gas canister is visible to the right

Eyesore: the damaged vehicle has not been removed after a month

He argued it was only a crime if they had been set alight without the owner’s knowledge or permission or if the fires had posed a risk to public safety.

Despite the first fire closing the road and being metres from motorists, the spokesman claimed neither of the fires posed a safety risk and the laybywas an “isolated area”.

He added: “Abandoned vehicles are primarily the responsibility of Essex Highways. It may be that setting a caravan on fire in public is an offence for another agency to look at, but these were not police matters.”

Dave Lovett, 64, from Honiley Avenue, Wickford, who runs Benfleet Glass in London Road, Benfleet, was astonished by the police’s decision.

He said: “It is absurd to say it is not a crime. What message does that send out to people prepared to do this?”

Dumping ground: The caravans make a grim site at the south-eastern entrance to Basildon

The eyesore caravans are still next to the A130 more than a month after the first blaze because no-one has taken responsibility to remove them.

Essex County Council, the highways agency, claimed it was the responsibility of Castle Point Council, because they were off the road, but their officials referred the matter to Basildon Council, claiming the caravans were on their territory.

However, the Echo’s enquiries have since been passed back to Essex County Council.